Auckland-based Donaldson - the former New Zealand sprinter - runs the same session for players in his home city, and he tries to catch up with others around the country as much as possible.

The players are asked to do 4x50m sprints, then 4x100m, 2x200m, 4x50m, 3x100m and 1x200m.

"It doesn't sound too much volume, but it's all about trying to get them to cope with running faster at a higher intensity," Donaldson said.

"Because the game's getting so quick and you have to be so athletic these days, it's dealing with a few different types of things, from resilience, to their speed and their power."

Then there's a gym session in the afternoon, while five other days of the week the players have two sessions to complete their individual programmes.

"They all do the same stuff, apart from the bowlers, obviously, so they've got to be physically the best out of all them because they're the ones that have to do the most, in the aspect of load."

During the sprint session in Hamilton, Boult was a clear leap ahead, always finishing first, and Donaldson rated him as physically one of the best in the squad across everything from strength to speed.

"But different types of athletes have different specialties, like BJ's a lot smaller, but he's agility-wise very good."

As much as the players despise the session, it makes them feel good afterwards, and there is a competitive element which comes out.

"It's horrible, yeah," Boult admitted. "The first couple are all right, and then it's just about striding out, but the lactic acid and all that hits you, and it's about hanging on. It's good to make the trip over the hill [from Tauranga] and have a good blowout.

"It does get a little bit competitive, but I think it's a lot about working together and kind of getting the most out of each session together."

Added Watling: "It's not much fun, but you feel better for it the next day. So it's good to get it done and finished."

Donaldson is admired by the players. Boult rates him as "first-class" and gave him a lot of credit for getting him in the shape he was, and for his performances on the park.